Problem: $ { {-4} \times \left[\begin{array}{rrr}{1} & {2} & {3} \\ {-2} & {-2} & {1}\end{array}\right] = {?} } $
To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-4}\times{1} & {-4}\times{2} & {-4}\times{3} \\ {-4}\times{-2} & {-4}\times{-2} & {-4}\times{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-4} & {-8} & {-12} \\ {8} & {8} & {-4}\end{array}\right]}$